1. Field of the Invention
The present invention relates to a light source device including a light-emitting portion that generates a light beam by an electric discharge between electrodes, and sealing portions provided on both sides of the light-emitting portion, and a projector.
2. Description of Related Art
Conventionally, a projector that forms an optical image by modulating a light beam irradiated by a light-emitting tube of a light source device in accordance with image information and projects the optical image in an enlarged manner has been used. In recent projectors, in order to clearly display the projected optical image, it is required to increase the illuminance of a light source lamp (light-emitting tube).
Since a great amount of heat is generated by the light-emitting portion of the light-emitting tube in accordance with the increase in the illuminance, cooling air is blown by a cooling fan etc. to control the temperature of the light-emitting tube (see Japanese Patent Laid-Open Publication No. 2002-107823(FIG. 1)).
However, since the temperature varies in accordance with the change in the flow rate and flow direction in the above arrangement where the light-emitting tube is cooled solely by the cooling air, it is difficult to control the temperature of the light-emitting tube at a predetermined temperature.
Further, in the Japanese Patent Laid-Open Publication No. 2002-107823, though the temperature of the light-emitting tube is controlled by cooling the light-emitting tube when the temperature of the light-emitting tube is high, the temperature is not controlled at a predetermined temperature by heating the light-emitting tube when the temperature of the light-emitting tube is low, e.g. immediately after a power switch is on.